1. Field of the Invention
The present invention relates to a control device for a vehicle AC (alternating current) generator and, more particularly, relates to one to which a power generation command is inputted from the outside of a body, and which transmits power generation control condition to the outside of the body.
2. Description of the Related Art
In a known device (Japanese Unexamined Patent Publication No. H8-238000), there is disclosed a vehicle charging device which outputs power generation control condition of a generator to the outside and forcibly controls a power generation state from the outside. When power generation operation is performed by a power generation command from the outside, operation is performed as specified by the command; and when the power generation command from the outside is not present, voltage control is performed.
In Japanese Unexamined Patent Publication No. H8-238000, power generation control is performed by the power generation command from an outside controller (ECU). When the power generation command is received from the outside controller, power generation can be controlled only as specified by the power generation command. That is, even when a power generation command that is harsh for the generator is received, the generator generates power as specified by the power generation command; as a result, the generator is burned out. In the case where the generator is designed so as not to be burned out even when the power generation command that is harsh is received, only considerably low production of electricity can be obtained or the generator becomes much larger.
For example, a generator, which supplies a field current from a DC output voltage by a system in which the DC output voltage is variable, can be operated at the maximum field current at low voltage output. However, when the maximum field current flows at high voltage output, an excessive field current flows due to high voltage and thus the generator is burned out. For this reason, a method in which the field current is detected and the maximum field current is restricted is known (Japanese Unexamined Patent Publication No. H3-45200). However, it is not known whether or not an outside controller is restricted only by being restricted; and therefore, for example, it becomes difficult to stabilize engine rotational speed.